I will admit to being one of the people who when this first came out was pretty flip about it. I'm much more neutral now; we had a meeting yesterday and there were some jokes going on about it but the mood was a little more nervous. I think remaining as calm and rational as possible is the correct course- the folks on the "We all gone die, buy all the TP and bottled water" side are just as bad as the "Oh, this is just a big scare for nothing, Coronavirus is a conspiracy" people.
This issue with stock piling supplies becomes a real problem, and this is why: even if people don't have a hoarder mentality, they might be tempted (as I have been) to pick up extra of stuff out of fear of other shiny happy people buying it all up. I have 3 other humans at my house, who all burn through toilet paper. I buy it by the giant economy bundle in _normal_ times. What happens if there's a concern the store might be sold out of it when we get low? I have to admit, I've been to the store like 3 times this week already, because every time I get home I look at our stock of household supplies and go, "Hmm, only one bottle of dishwasher soap left, crap, better go grab some more". We really need to develop an inventory system to track stuff so we a) don't hit the "danger zone" and b) can limit our shopping tips as much as possible.
I have noticed that, TP, hand sanitizer, and bottled water aside, other grocery store provisions seem to be holding out.
Minimizing social contact isn't going to stop the disease from spreading, but it can slow it down, and flatten out the affectivity curve. If 40% of us got it in the next month, our health care system would be overloaded (see: Italy) but if 70% of the US gets it over the next year, it won't be as bad. It's purely a numbers game.
Finally, I haven't seen it mentioned yet, but anyone who has any land (or even room for some pots) ought to start planning a garden. Not only will it get you outside, and in some fresh air and soak up some vitamin D, it'll give you something to do while you're socially distancing, you'll get the best tasting vegetables ever, and you'll further reduce how much you have to go to the store to buy produce.